Lewis structure of SF₆
48 valence electrons. Six S-F single bonds, with no lone pair on S, so S has 12 electrons around it (an expanded octet).
Lewis structure
48 valence electronsi
An expanded octet: S has 12 electrons around it.
Formal charges: none
Why this shape
- S has 6 valence electrons. It uses six in six single bonds to F, so none are left over.
- Steric number = six sigma bonds + no lone pairs = 6, so S is sp³d² hybridised.
- Six electron pairs point to the corners of an octahedron (octahedral electron geometry). With no lone pairs the atoms take the same shape: octahedral.
- All the bond pairs repel each other equally, so the angle is the ideal 90°.
- The bond dipoles cancel in the symmetric octahedral shape, so SF₆ is non-polar.
How to draw it
- Count the valence electrons: S 6 + 6 × F 7 = 48 valence electrons, 24 pairs.
- Put S in the middle and join it to the six outer atoms with single bonds.
- Give each outer atom lone pairs until it has an octet (H needs only two electrons), then put any electrons left over on the central atom.
- Result: six S-F single bonds, with no lone pair on S, so S has 12 electrons around it (an expanded octet).
- Formal charge = valence electrons − lone pair electrons − number of bonds. Here: none.
Class 11, Chapter 4 Chemical Bonding and Molecular Structure.
Lewis structure of SF6: quick answers
How many valence electrons are in SF6?
S 6 + 6 × F 7 = 48 valence electrons, 24 pairs.
What are the formal charges in the Lewis structure of SF6?
Every atom has a formal charge of zero.
How many lone pairs are in the Lewis structure of SF6?
18 in all, none on the central S.